Nausea and vomiting in pregnancy (NVP) occurs in about 75% of all pregnancies and is a favorable prognostic symptom in that it is more likely to occur in women who do not abort naturally and have a longer gestation and higher birth weight infant. This study is a prospective investigation to determine what variables mediate this apparently protective effect of NVP upon the fetus. The variable in the study include demographic factors, maternal nutrition, weight gain, smoking and drug ingestion, symptoms of NVP, and fetal outcomes. After adjusting for socioeconomic and other pre-pregnancy factors a nonsymptomatic NVP sample will be compared to a symptomatic sample to look for any correlation between fetal outcome and the intervening variable assoiciated with NVP.